Chapter 46.
Animal Reproduction
AP Biology
2005-2006
Sexual & asexual reproduction
 Asexual


offspring all have same genes (clones)
no variation
 Sexual


AP Biology
gametes (sperm & egg)  fertilization
mixing of genes  variation
2005-2006
Parthenogenesis
 Development of an unfertilized egg

honey bees
 drones = males produced through
parthenogenesis  haploid
 workers & queens = females produced from
fertilized eggs  diploid
AP Biology
queen
worker
drone
2005-2006
Different strokes…
gay
penguins
parthenogenesis in aphids
“lesbian” lizards
AP Biology
2005-2006
sex-change in fish
Hermaphrodites
 Having functional
reproductive system
of both sexes
earthworms mating
flat worm
AP Biology
2005-2006
Fertilization
 Joining of egg & sperm

external
 usually aquatic animals

internal
 usually land animals
AP Biology
2005-2006
Development
 External


development in eggs
fish & amphibians in water
 soft eggs= exchange across membrane

birds & reptiles on land
 hard-shell amniotic eggs
 structures for exchange of food, O2 & waste

sharks & some snakes
 live births from eggs
 Internal

placenta
 exchange food & waste

AP Biology
live birth
2005-2006
Adaptive advantages?
 What is the adaptive value of each
type of sexual reproduction
number of eggs?
 level of parental of care
 habitat?

AP Biology
2005-2006
Human Reproduction
AP Biology
2005-2006
Reproductive hormones
 Testosterone


from testes
functions
LH &
FSH
 sperm production
 2° sexual
characteristics
 Estrogen


from ovaries
functions
 egg production
 prepare uterus
for fertilized egg
 2° sexual
characteristics
AP Biology
testes
or
ovaries
2005-2006
Sex hormone control in males
Hypothalamus
GnRH
Pituitary
FSH & LH
Testes
testosterone
Body cells
AP Biology
2005-2006
Male
reproductive
system
 Sperm production
over 100 million produced per day!
AP Biology
 ~2.5 million released per drop!

2005-2006
Male reproductive system
 Testicles

produces sperm & hormones
 Scrotum

sac that holds testicles outside of body
 Epididymis

where sperm mature
 Vas deferens

tubes for sperm to travel from testes to penis
 Prostate, seminal vesicles,
Cowper’s (bulbourethal) glands


AP Biology
nutrient rich fluid to feed & protect sperm
buffer to counteract acids in vagina
2005-2006
seminiferous tubule
Male reproductive system
sperm
spermatocytes
 Testes & epididymis

sperm production &
maturation
 Glands

AP Biology
seminal vesicles,
prostate, bulbourethal
 produce seminal fluid =
2005-2006
nutrient-rich
Spermatogenesis
Epididymis
Testis
Coiled
seminiferous
tubules
Germ cell
(diploid)
1°
spermatocyte
(diploid)
MEIOSIS I
2°
spermatocytes
(haploid)
MEIOSIS II
Vas deferens
Spermatids
(haploid)
Spermatozoa
Cross-section of
seminiferous tubule
AP Biology
2005-2006
Female reproductive system
AP Biology
2005-2006
Female reproductive system
 Ovaries

produces eggs & hormones
 Uterus

nurtures fetus; lining builds up each month
 Fallopian tubes

tubes for eggs to travel from ovaries to
uterus
 Cervix

opening to uterus, dilates 10cm (4 inches)
for birthing baby
 Vagina

AP Biology
birth canal for birthing baby
2005-2006
Female reproductive system
AP Biology
2005-2006
Start here
AP Biology
2005-2006
LH
Menstrual cycle
FSH
Hypothalamus
GnRH
egg development
ovulation = egg release
corpus luteum
Pituitary
FSH & LH
estrogen
progesterone
Ovaries
lining of uterus
estrogen
Body cells
AP Biology
days 0
7
14
21
2005-2006
28
Egg maturation in ovary
 Corpus luteum

AP Biology
produces
progesterone
to maintain
uterine lining
2005-2006
Female hormones
 FSH & LH



release from pituitary
stimulates egg development & hormone release
peak release = release of egg (ovulation)
 Estrogen



released from ovary cells around developing egg
stimulates growth of lining of uterus
lowered levels = menstruation
 Progesterone



AP Biology
released from “corpus luteum” in ovaries
 cells that used to take care of developing egg
stimulates blood supply to lining of uterus
lowered levels = menstruation
2005-2006